2006-12-13 Wx Discussion and Forecast
Discussion for Wednesday, December 13, 2006
Another day, another half inch of precip all over the place. Good mold-growing weather.
Lots of straight flow off the ocean still causing occasional showers, some of them quite productive, over the ARB and Sacramento area. We’ve been watching a trailing cold front scheduled for Thursday evening and into Friday morning as a focus for precipitation perhaps approaching IOP criteria (1 inch for cold events, 2 for warm … although we’d settle for less). The nwp suggests that maybe ¾ inch should fall with this, probably less with the front itself than the warm/moist advection ahead of it; either way, this doesn’t look like an IOP. It should be noted that a small minority of GFS ensemble runs do have IOP weather starting after midnight Friday and lasting through Friday afternoon.
As discussed yesterday, there will be a broad trough developing along the west coast, but it doesn’t really spin up until it gets inland, and then when it does it’s too far south. Ironic for those of us who have been watching tons of precipitation fall to our north all week long. Anyway, precip associated with this development would be Saturday afternoon at the earliest, so we’ll save a decision on that for tomorrow, but right now the probability of an IOP associated with the digging trough is 20%.